Pushrod length
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Cross-Country
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I tested it on the exhaust valve and it was the same. I would like a bit narrower sweep but this will be a street truck. Now to order pushrods and check valve clearance
Logistics Pro
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https://www.ford-trucks.com/forums/1...l#post21750459
Cargo Master
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You can take an old stock ford roller lifter apart, remove the spring, flip the plunger and now you have a solid lifter:
https://www.ford-trucks.com/forums/1...l#post21750459
https://www.ford-trucks.com/forums/1...l#post21750459
Cargo Master
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Cross-Country
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My only concern is that when I torqued the rocker down with the shimmed lifter, it took about a full rotation to hit 20 lbs. I hope that it hits the 1/4 to 1/2 rotation to torque to hit the .030 preload.
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Cross-Country
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I should have paid more attention in my geometry class. I could not get satisfied with my setup. I revisited it tonight and here is where I am. I was able to get a good sweep pattern with the pushrod at 6.4 however it takes 1.3 turns of the rocker bolt to get to torque. If I shorten the pushrod to just under 6.3, it takes just over 1/4 turn to get to proper torque of the rocker bolt. The problem is that the sweep pattern gets wider and it much closer to the intake side. It seems like I will be needing to shim the rocker to correct the geometry to get the proper preload.
Cargo Master
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With this type of valve train pushrod length should make no difference in the sweep pattern. The pivot height relative to the height of the valve stem tip is not changed when you change the length of the pushrod.
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Cross-Country
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Dave thanks for the reply and info. So help me understand. With the shorter length pushrod, the sweep pattern looks wider and more toward the intake side. At 6.4, it is tighter and pretty much in the center. If rod length does not make a difference, why am I seeing the sweep pattern change when I change the length? From what I can calculate, a .030 shim under the rocker seems to be about right to get a good sweep and preload. I need to put my dial on it this weekend to actually check the preload rather than trying to use the rotation method. Thanks again for the reply and help
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Fleet Mechanic
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This is a lot more technical than I know with geometry! I did want to share that .030 should
put you at about 1/4 turn to get the torque. When I had my heads shaved, I played around with shim heights to get the torque in how I wanted it. It seemed to be about .010 to remove every 1/4 turn.
put you at about 1/4 turn to get the torque. When I had my heads shaved, I played around with shim heights to get the torque in how I wanted it. It seemed to be about .010 to remove every 1/4 turn.
Cargo Master
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Dave thanks for the reply and info. So help me understand. With the shorter length pushrod, the sweep pattern looks wider and more toward the intake side. At 6.4, it is tighter and pretty much in the center. If rod length does not make a difference, why am I seeing the sweep pattern change when I change the length? From what I can calculate, a .030 shim under the rocker seems to be about right to get a good sweep and preload. I need to put my dial on it this weekend to actually check the preload rather than trying to use the rotation method. Thanks again for the reply and help
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Cross-Country
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You shouldn't see a difference if the only thing that you're changing is the pushrod length. But if you're also swapping around the shim under the trunnion(altering its height) then you should see a change. Sweep pattern gets wider with the shorter rod because the roller is moving out farther during the first 1/2 or so of valve opening before stopping and sweeping back inward. But that's only if you also lower the height of the trunnion. Otherwise it would just change the amount of preload that you're putting into the lifter. This of course could alter the pattern because it allows the lifter more room to collapse under spring load and alter your readings.
Cargo Master
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It should be perpendicular to the axis of the valvetrain. On the Windsor style head the stamped out channel is supposed to line it up. I would say that it is certainly possible that it could be off a little bit or loose enough to cause some misalignment when the bolt it torqued in place. What I've had to do in the past it hold the rocker arm by the ends of the trunnion using a wrench to hold it in place while I tighten down the bolt. Once it's tight it's tight and it won't move. Some heads do sacrifice this alignment if the valve centerlines have been moved around from stock. Some run the rockers at a slight angle which is somewhat incorrect while others keep the rockers running straight but slightly off center on the end of the valve stem. This is ok.
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